[Advances in the Study on Marker Genes in transgenic Plants.]

Plant transgenic engineering is becoming more and more important in the world. The safety of selectable marker genes in the transgenic plants has been noticed widely. The new advances of selectable markers in transgenic plants were reviewed in this paper in three aspects. The first is the establishment of transformation systems allowing resistant marker genes to be eliminated from the transgenic plants, including co-transformation, site-specific recombination and transposition, as well as other methods. In these ways, the transgenes can be inserted into transgenic plants more than once. The second is the utilization and development of bio-safe positively selective marker genes, mainly referred to the carbohydrates metabolism genes, the stress- resistant enzymatic genes and the green fluorescent protein(GFP) gene. At the same time, the mercuric reductase genes, the key genes for chloroplast synthesis and other genes should also be quickly developed as markers. The third is the establishment of marker-free and skelecton-free transformation vector systems, which are efficient and simple. The prospects in application of these novel methods, marker free and safe selectable markers are also viewed in the article.